1. Field of the Invention
The present invention relates to communication receivers and in particular to a method and apparatus for generating a remote alert signal in a personal portable paging receiver.
2. Background Discussion
Communication systems in general and paging systems in particular using transmitted call signals have attained widespread use for calling selected receivers to transmit information from a base station terminal to the receiver. Briefly, a simple paging receiver includes a receiver, a decoding unit, and alert circuitry. The receiver receives selective calling message signals while the decoding unit assures that only selective calling messages intended for the particular paging receiver are processed by the paging receiver. In response to decoding information intended for the paging receiver, the alert circuitry alerts the user that a selective calling message is received. This is accomplished by activating one of a plurality of alert annunciators such as a light, a speaker, or a vibratory means to produce an alert signal to notify the user of a received message.
Due to the versatility of paging receivers, the population of paging receivers has increased dramatically within the last several years. Since a growing percentage of the pager user population is the business user, a difficulty has arisen due to the type of wearing apparel. Traditionally, a belt worn paging receiver as disclosed in U.S. Pat. No. 4,635,836 has shown great popularity. However, with the increase of paging receivers into the business community, paging receiver manufacturers have been providing smaller paging receiver units with user option removable belt clips or pocket watch style lanyards which clip the pager to the user's apparel. Typical of the pocket watch style lanyard is Motorola's lanyard manufactured under their designation NRN4916A. These type of lanyards have a clip on one end with the paging receiver attached to the other end. In practice, the clip is typically attached to a belt loop or pocket with the paging receiver being placed in the pocket or the like. Unfortunately, the use of these pocket watch style lanyards has often resulted in the alert signal, generated by the paging receiver, to be obstructed by the apparel of the user. In particular, for a vibration alert, the tactile sensation being transmitted in the paging receiver to the user has been less than adequate due to the low or absence of physical coupling to the paging receiver user. This has also been a significant drawback for those paging receiver users in high ambient noise areas or non-intrusive noise areas for which vibratory annunciation is the only viable option for notification.
Furthermore, the vibratory annunciation mechanism has always been included in the paging receiver device which has restricted the reduction in size of the paging receiver. Therefore, it would be desirable to have an alerting device being physically separated from the paging receiver while remaining responsive to the alert circuitry of the paging receiver. Ideally, the alerting device is attached to a location on the user which enhances the detectability of the alert signal. However, one problem with a remote alerting device is accidentally severing the communication channel between the alerting device and the paging receiver, thus resulting in lost communication between the alerting device and pager. This is extremely undesirable since the paging user will lose the major function of the paging receiver, namely the alert capability. Another problem arises when the communication channel takes the form of an electrical cable between the alerting device and paging receiver. In this instance, the kinking and twisting of the cable is very uncomfortable and undesirable.